Sleep hygiene and its impact on health 1:30
(CNN) -
Older adults who have major trouble falling asleep and who experience frequent nighttime awakenings are at high risk of developing dementia or dying early from any cause, a new study finds.
"These results contribute to the existing knowledge that sleep plays a very important role, each and every night, in reducing our long-term risk of neuronal cognitive impairment and all-cause mortality," said study author Rebecca Robbins, an instructor of medicine at Harvard Medical School who specializes in sleep research.
The connection between sleep, dementia, and premature death from any cause is especially troubling, experts say, because of the sleeping habits of Americans and people around the world.
According to the World Sleep Society, lack of sleep threatens the health of up to 45% of the world's population.
Does the night mode of your cell phone work?
We tell you 0:47
Depending on our age, we are supposed to sleep between seven and ten hours each night.
But one in three Americans doesn't get enough sleep, according to the US Centers for Disease Control and Prevention.
Additionally, between 50 and 70 million Americans struggle with sleep disorders like sleep apnea, insomnia, and restless leg syndrome, which can ruin a good night's rest.
The CDC calls it a "public health problem," because sleep disruption is associated with an increased risk of conditions, including diabetes, stroke, cardiovascular disease and dementia.
An 8-year study
The study, published recently in the Journal of Sleep Research, analyzed data collected by the National Health and Aging Trends Study (NHATS).
The agency conducts annual in-person interviews with a nationally representative sample of 6,376 Medicare beneficiaries.
advertising
Data from between 2011 and 2018 were examined for the new study, with a focus on people in the highest-risk category.
They are those who said they had trouble sleeping "most nights or most nights."
Why do women suffer more from insomnia?
1:14
The self-reported sleep difficulties by the study participants were then compared to each participant's medical records.
Because the NHATS study collected annual sleep data, the new study was able to track all of each person's difficulties for the entire eight years, rather than just taking a snapshot in time.
This was one of the strengths of the study, Robbins said, because "sleep health can come and go over the years."
Another strength of the study was the ability to differentiate the impact of having some difficulty falling asleep versus frequent nocturnal awakenings on any risk of dementia and death.
12 Questions and Answers About Sleep: Do You Have a Sleep Deficit?
What Causes Insomnia?
Is it good to take a nap?
"We found a strong association between frequent difficulty falling asleep and nocturnal awakenings and dementia and premature death from any cause, even after controlling for depression, sex, income, education, and chronic conditions." Robbins said.
Different sleep problems
People who had trouble falling asleep most nights had a 44% higher risk of premature death from any cause, the study found.
Those who said they often woke up at night and struggled to get back to sleep had a somewhat higher risk: a 56% higher risk of premature death from any cause.
The risk of dementia was similar.
People who reported that they routinely experienced difficulty falling asleep had a 49% increased risk of dementia.
Meanwhile, those who often woke up at night and had difficulty falling back to sleep had a 39% higher risk.
Know the consequences of having poor quality sleep 5:51
But it was the people who had a lot of trouble falling asleep and staying asleep who had the highest risk of dementia or dying prematurely from any cause.
"We found a 56% increased risk of dementia and an 80% increased risk of all-cause mortality over the next eight years among those who experienced both concurrent sleep difficulties - falling asleep or waking up from sleep," Robbins said.
Additional studies on sleep problems
High-quality sleep is critical to our overall health and cognitive reserve, experts say.
A 2017 study found that healthy middle-aged adults who slept poorly for just one night produced a large number of beta amyloid plaques.
This is one of the characteristics of Alzheimer's disease.
Amyloid beta is a sticky protein compound that disrupts communication between brain cells.
Finally, it kills cells as it accumulates in the brain.
Your lifestyle can reduce your risk of dementia, even if you have a genetic risk
A week of interrupted sleep increased the amount of tau.
It is the protein responsible for the tangles associated with Alzheimer's, frontal lobe dementia and Lewy body disease, the study found.
Another 2017 study compared dementia markers in cerebrospinal fluid with self-reported sleep problems.
It found that subjects who had sleep problems were more likely to show evidence of tau pathology, brain cell damage, and inflammation.
That was true even when other factors such as depression, body mass, cardiovascular disease, and sleep medications were taken into account.
The number of hours of sleep, key
Not getting a full seven to eight hours a night is also linked to dementia, according to a study published in April.
After following nearly 8,000 people for 25 years, the study found an increased risk of dementia with a "sleep duration of six hours or less in their 50s and 60s" compared to those who slept seven hours a night.
Furthermore, persistent short duration of sleep between the ages of 50, 60 and 70 was also associated with a "30% increased risk of dementia" regardless of "sociodemographic, behavioral, cardiometabolic and mental health factors", including depression, according to the study .
What to do with dementia?
Medical science does not have a current cure for dementia, but there are things you can do to reduce your risk.
There are several great ways to keep your brain and body healthy, experts say.
Quitting smoking, drinking only in moderation, if you drink at all, eating a well-balanced diet, exercising, staying mentally active, and controlling blood pressure and cholesterol levels are some of them.
Dementia grows among Hispanics 3:17
You can also address any sleep problems by training your brain to sleep better.
Experts call it "sleep hygiene," and they suggest establishing a bedtime routine designed to relax and calm you.
It should not include a television, smartphone, or other blue light-emitting device at least an hour or two before bedtime.
Other tips include having a comfortable bed and pillow.
Also, keep the bedroom cool, quiet, and dark and avoid caffeine and alcohol for hours before bed.
Whatever you do, don't miss out on sleep: If you follow these tips and you can't seem to relax or your sleep keeps getting worse, be sure to contact your doctor or a sleep health professional.
Sleep quality Dementia premature death